The Respironics BiPAP S/ST/STD30 device is designed to augment the breathing of a spontaneously-breathing adult patient. Unlike ventilators, it will not completely take over the breathing for the patient, but instead helps a patient who has chronic respiratory failure, difficulty breathing, or obstructive sleep apnea; it is administered via a mask and does not require intubation of the patient. The device automatically synchronizes with the patient’s respiratory pattern, cycling between IPAP and EPAP (breath in and breath out). The S/T model can also be set to a timed mode, where the clinician sets the BPM (breaths per minute) and %IPAP; or it can be set to a combination of Spontaneous and Timed operation, where the unit cycles in response to the patient’s breathing rate, but switches to the timed operation if the patient fails to take a breath within the timed interval.
The device also analyzes flow patterns throughout each breath and makes internal adjustments for any air leaks in the system.
The BiPAP S and S/T differ in that, like the abbreviations indicate, the BiPAP S is only capable of Spontaneous operation, whereas the S/T model can be programmed for both Spontaneous and Timed operation.
The S/T unit can also be used for CPAP (Continuous Positive Airway Pressure) operation. In BiPAP operation, the unit gives two pressures, one for inhalation and one for exhalation, lowering the pressure during the exhale, which is often more comfortable for the patient, but some patients will require CPAP.
The unit runs on AC power, but optional 12-volt battery operation is possible. It can also be attached to an optional humidifier to relieve the effects of nasal dryness. Respironics does not offer the battery for sale; the correct model can be obtained at Sears or similar department stores, or at Marine supply stores. Use a 100 Amp-hour, 12-volt deep cycle marine battery, attached to the BiPAP unit using the Respironics DC Interface module (Part # 552097). The DC Interface module also requires a battery adapter cable (# 532209).
Airway Pressure Monitor
BiPAP, CPAP, or volume ventilator units can be attached to the optional Airway Pressure Monitor (RPST/AWP), which provides constant analysis of airway pressure and will sound an audible alarm if pressure goes outside preset pressure limits. The older Respironics model with analog gauge (shown below) is still available in limited quantities; the newer model has a digital pressure display.